Page 9 - Mechanics Analysis Composite Materials

vi Preface

Soviet and then Russian projects in composite technology. This governs the list of
problems covered in the book which can be referred to as material problems
challenging designers and determines the third of its specific features - discussion is
illustrated with composite parts and structures built within the frameworks of these
projects. In connection with this, the authors appreciate the permission of the
Russian Composite Center -Central Institute of Special Machinery (CRISM) to use
in the book the pictures of structures developed and fabricated in CRISM as part of
the joint research and design projects,
The book consists of eight chapters progressively covering all structural levels of
composite materials from their components through elementary plies and layers to
laminates.
Chapter 1 is an Introduction in which typical reinforcing and matrix materials as
well as typical manufacturing processes used in composite technology are described.
Chapter 2 is also a sort of Introduction but dealing with fundamentals of
mechanics of solids, i.e., stress, strain, and constitutive theories, governing
equations, and principles that are used in the next chapters for analysis of
composite materials.
Chapter 3 is devoted to the basic structural element of a composite material -
unidirectional composite ply. In addition to traditional description of microme-
chanical models and experimental results, the physical nature of fiber strength, its
statistical characteristics and interaction of damaged fibers through the matrix are
discussed, and an attempt is made to show that fibrous composites comprise a
special class of man-made materials utilizing natural potentials of material strength
and structure.
Chapter 4 contains a description of typical composite layers made of unidirec-
tional, fabric, and spatially reinforced composite materials. Traditional linear elastic
models are supplemented in this chapter with nonlinear elastic and elastic-plastic
analysis demonstrating specific types of behavior of composites with metal and
thermoplastic matrices.
Chapter 5 is concerned with mechanics of laminates and includes traditional
description of the laminate stiffness matrix, coupling effects in typical laminates and
procedures of stress calculation for in-plane and interlaminar stresses.
Chapter 6 presents a practical approach to evaluation of laminate strength. Three
main types of failure criteria, i.e., structural criteria indicating the modes of failure,
approximation polynomial criteria treated as formal approximations of experimen-
tal data, and tensor-polynomial criteria are analyzed and compared with available
experimental results for unidirectional and fabric composites.
Chapter 7 dealing with environmental, and special loading effects includes
analysis of thermal conductivity, hydrothermal elasticity, material aging, creep, and
durability under long-term loading, fatigue, damping and impact resistance of
typical advanced composites. The influence of manufacturing factors on material
properties and behavior is demonstrated for filament winding accompanied with
nonuniform stress distribution between the fibers and ply waviness and laying-up
processing of nonsymmetric laminate exhibiting warping after curing and cooling.